#include <iostream>
#include <sstream>
#include <string>

std::string vowels("aeiouAEIOU");

bool contains(const std::string& s, char letter)
{
    return s.find(letter) != std::string::npos;
}

bool is_vowel(char ch)
{
    return contains(vowels, ch);
}

std::istringstream in("These are some words\n.  Everyone should know them.");

int main()
{
    std::size_t vowels = 0;
    char ch;

    while (in >> ch)
        vowels += is_vowel(ch);

    std::cout << "Counted " << vowels << " vowels.\n";
}